Both false prophets and teachers lack faith in God and in the truth of God. Both are displeasing to God. Both lead people away from God, down a path of assured self destruction.
We need to have an unshakable confidence in the Word of God if we are going to be protected from false teachers. Today's verses in 2 Peter 1:16-21 focus is on having a confidence in the scriptures that will protect us from deception. Several thing contribute to confidence in God's Word. How is your confidence? We will find out!